/Engine/Source/Runtime/Engine/Classes/Camera/PlayerCameraManager.h
Turns on camera fading at the given opacity. Does not auto-animate, allowing user to animate themselves. Call StopCameraFade to turn fading back off.
virtual void SetManualCameraFade ( float InFadeAmount, [FLinearColor](API\Runtime\Core\Math\FLinearColor) Color, bool bInFadeAudio )